Method for manufacturing heat-stable structured layers based on expoxy resin

Abstract

A method of manufacturing heat-stable structured layers by applying a radiation-sensitive soluble photopolymer in the form of a layer or film on a substrate, irradiating the layer or film through a negative pattern with actinic light or through the use of a light, electron, laser, or ion beam, removing the non-irradiated layer or film parts and, optionally tempering the remaining parts is described wherein the photopolymer comprises an addition reaction product of an olefinically unsaturated monoisocyanate and a hydroxyl group-containing epoxy compound. The invention provides a cost-effective method of manufacturing dimension-precise structured layers of high quality in a single coating process. The layers produced with this method even resist high thermal and mechanical stresses in immersion soldering processes, and protect circuit surfaces effectively and permanently against moisture and corrosion. They are suitable for use, in particular, as solder resist and insulating layers in microelectronics.

We claim: 
     
       1. A method for manufacturing heat-stable structured layers based on epoxy resin, which comprises the steps of applying a radiation-sensitive soluble photopolymer in the form of a layer or film on a substrate, irradiating the layer or film through a negative pattern with actinic light or by using a light, electron, laser, or ion beam, and removing the non-irradiated layer or film portions, wherein the photopolymer comprises an addition reaction product of an olefinic unsaturated monoisocyanate, selected from the group consisting of an isocyanate having at least one methacrylate group, and the addition reaction product of hydroxyethyl acrylate or methacrylate and 2,4-diisocyanatotoluene, and a hydroxyl group-containing epoxy compound. 
     
     
       2. The method according to claim 1, further comprising the step of tempering. 
     
     
       3. The method according to claim 1, wherein the photopolymer is employed together with a light- or radiation-sensitive copolymerizable compound. 
     
     
       4. The method according to claim 3, wherein the copolymerizable compound contains an acrylate or methacrylate group. 
     
     
       5. The method according to claim 1 wherein the photopolymer is employed together with photoinitiator or a photosensitizer or a mixture thereof. 
     
     
       6. The method according to claim 5, wherein the photoinitiator or photosensitizer is selected from the group consisiting of alpha-halogenacetophenones, dialkoxyacetophenones, benzoylphosphine oxides, and Michler's ketone. 
     
     
       7. The method according to claim 1, wherein the epoxy compound in part contains aromatic groups. 
     
     
       8. The method according to claim 7, wherein the  epoxy compound has an epoxide equivalency weight of 600 to 6000. 
     
     
       9. The method according to claim 1, wherein the photopolymer is employed together with an epoxide curing agent. 
     
     
       10. The method according to claim 1, wherein the photopolymer is employed together with a mineral filler material. 
     
     
       11. A heat-stable structured layer, produced according to claim 1. 
     
     
       12. A durable, protective solder resist and insulating layer for use in microelectronics technology, which comprises a structured layer produced according to claim 1. 
     
     
       13. A resist with intermediate protective function for use in structure transfer processes by electroplating, wet and dry etching, and ion implantation, which comprises a structured layer produced according to claim 1. 
     
     
       14. A protective and insulating material for use in electrical engineering, including semiconductor technology, which comprises a structured layer produced according to claim 1. 
     
     
       15. A damping substance for surface wave filters, which comprises a structured layer produced according to claim 1. 
     
     
       16. An alpha-ray protector for the cell fields of a memory component, which comprises a structured layer produced according to claim 1. 
     
     
       17. An orientation layer for liquid crystal displays, which comprises a structured layer produced according to claim 1. 
     
     
       18. A dielectric material for use in multiple layer circuits, which comprises a structured layer produced according to claim 1.